Electric signaling



Feb. 22, 1944. E, BRUCE ETAL ELECTRIC SIGNALING Filed June ,27, 1942 2 Sheets-Sheet 1 /oko l E. BRUCE /NVENTO/R. c. M4 m55 MW 144 QM l ATTORN V Feb. 22, E BRUCE ETAL ELECTRIC S IGNALING Filed June 27, 1942 2 Sheets-Sheet 2 50a OOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOO OOOOOOOOOOO OO vOOO O OOOOOOOOOOO O O OOOOOOOOOOO O O O TH 00000000000 o O OOOOOOOOOOO O O OOOOOOOOOOO O O OOOOOOOOOOO O O OOOOOOOOOOO O OO O OOOOOOOOOOO OO OOOO OO OOOOOOOOOOC` OOO OOOOO OO 50N 00000000000- Oo Oo OOOOO OO O O OOOO OO O O OOO O /JH OO O OO O OO OO OO OOO O O O OOOOOOOOOOO OO OOOO OO mman/1 m OO OO- O OO O OOOOOOOOOOOO OO OOOO OO OOOOOOOOOOOO OO OOOO OO OO OO O OO O 502 O O O O O Q-TH O O OO O OOO OO O v Y O O OOOOOOOOOOOO OO OOO OO 503/ 0- rE/vs 504/ a-TE/vs 505 9-rE/v5 -/G :L /G4 EBRUCE //5 Y /09 //a /NVENTORC/MTHES Patented Feb. 22, 1944 ELECTRIC SIGNALING Edmond Bruce, Bed Bank, and Robert C. Maplewood, N. J., animo Laboratories, Incorpora corporation ot New Y Mailles. l n to Bell Telephone ted, New York, N. Y., a ork Application June 21, 1942. sex-iai No. 44a-:io 4 claims. (ci. 179-27) This invention relates to electric signaling, particularly when employed in connection with the operation of automatic telephone systems.

The objects of the invention are to obtain greater economy and simplicity than heretofore realized in the mechanisms used for identifying the lines. trunks, `or other electric circuits of a large group; to enable the use of economical types of photoelectric devices for detecting the identity of the line; to obviate the necessity of optical systems for focussing lthe light; and to eiect other improvements in systems o1' this general character.

The foregoing objects of the invention are realized in a system in which the lines of a group are identified and their designations determined by means of a coordinate ileld or array of signal lamps, representing individually the lines of the group, together with a coordinate arrangement of light-sensitive elements superimposed upon the lamp array for determining the location of any one of said lamps in the array in response to its illumination. More speciiically the signal lamps, which represent individually the speciiic lines of the group, such as the ten thousand lines in a telephone oiiice, are arranged on a decimal basis in a ileld of coordinate rows; and a plurality of light-sensitive elements, preferably in the form of continuous strips, are arranged in a grid array which is superimposed upon the lamp iield in such a way that the light from each lamp shines on the intersection of a light-sensitive strip in one coordinate direction and a light-sensitive strip in the' other coordinate direction. If it is assumed, for example, that the lamp array contains one hundred horizontal rows and one hundred vertical rows of lamps, the light-sensitive grid structure likewise comprises one hundred horizontal light-sensitive strips and one hundred vertical strips. In order to avoid the necessity of providing light-focussing means, the individual lamps are enclosed in cells and the light-sensitive grid structure is secured to the face of the array so that the light from each lamp shines directly on the intersection of the two corresponding strips and does not shine on any other strip. The currents generated in the light-sensitive strips. of which there are one hundred in one coordinate direction and one hundred in the other coordinate direction, may be amplified by any suitable means and applied to any well-known form of translating mechanism for indicating or registering the decimal designations of the lines represented by the lamp array.

Other features oi the invention will be described more fully in the following detailed speciilcatlon.

In the drawings accompanying the specincation:

lIiig. l is a conventional diagram of an automatic telephone system arranged for calling line identification;

Fig. 2 is an enlarged perspective detail of the lamp field shown in Fig. 1;

Fig. 3 is an enlarged plan view of the lamp iield;

Fig. 4 is an enlarged detail of one oi' the lightsensitive strips associated with the lamp eld; and

Fig. 5 illustrates the field or panel of lamps representing the subscribers lines in an oillce and serving to identify the lines by their numbers.

The present invention is particularly useful in systems that require the preparation oi tickets for the purpose of assessing a calling telephone subscriber for conversations held with other subscribers. Since these tickets are prepared automatically, it is necessary to determine the num ber of the calling line in order that the charge may be assessed against the proper party. However, the invention may be used in any type of system where it is desirable to determine automatically the identity of a line, trunk, circuit or other device. For example, it is often desirable to display the number of a calling party before an operator to whom the line has been extended, thereby eliminating the necessity for the operator to make an oral request or to perform a number-checking operation.

Referring to the drawings, the automatic telephone system illustrated in Fig. 1 comprises a large group of lines, usually ten thousand, which appear in the telephone central office in nonnumerical switches, such as ilnder switches. The line |00 illustrated in the drawings appears in the bank of line finder switch F which is associated with a first selector switch S. The selector switch S may have direct access to outgoing trunks, or, as shown, it may have access through a succeeding selector switch S-I to trunks outgoing to distant oilices such as the trunk 10|.

The designation or identity of eachla line that establishes a toll call over one of the outgoing trunks lill is obtained by a field of signal lamps mounted in a panel |02. This eld oi signal lamps includes a lamp for each of the ten thousand lines in the oillce, and each lamp represents the number oi the associated line. The lamps of a portion are arranged in decimal order in coordinate horizontal and vertical rows, there being one hundred horizontal rows and one hundred vertical rows, each row in both directions containing one hundred lamps. l

Referring for the moment to Fig. 5, which illustrates the lamp formation more clearly, the hundred horizontal rows are divided into ten equal of one hundred lamps representing the ten hundreds groups in the thousand. In like manner the ileld of lamps is divided into ten vertical groups representing the ten tens groups of all hundreds groups. For example, vertical groups 503, 504 and 505 represent respectively the No. 0,

No. 8 and No. 9 tens groups. Each of these tens groups contains ten vertical rows of lamps representing respectively the ten units designations.

Returning to Fig. 1, the lamp panel |02, which may be of any suitable material, is provided with one hundred rows of holes or apertures, and the lamps are mounted in these holes in horizontal and vertical rows so as to emit their light from the front of the panel as seen in the figure. The light from these lamps is directed to shine selectively upon a, network of photosensitive strips arranged immediately in front of the lamp panel. The photo-sensitive network consists of one hundred horizontal strips |03, |04, |05, |06, etc., which correspond to the thousands and hundreds digits, and one hundred vertical strips |01, |08, y

|09, ||0, etc., which correspond to the tens and units digits of the lines represented by the lam in the panel. y v

Each one of these photo-sensitive strips may comprise a backing of cloth or a plastic material such as glass or any other suitable materialonthe surface of which a coating of light-responsive substance is disposed. For example, these strips may be made, as seen in Fig. 4, by spraying bands |40, 4| of conductive material, such as silver, along the edges of a strip of insulating material |42 and then spraying the entire surface with some suitable photo-sensitive substance such as selenium. According to the substance employed a change in resistance is effected by light shining on the strip, producing a corresponding change of current in the associated circuit |43, or a change of potential is produced between the conductive bands and |4I, resulting in a corresponding current ow in circuit |43.

The grid or network of photo-sensitive strips is arranged as seen in Figs. 1, 2 and 3 in front of the lamp panel so that the horizontal and vertical rows of intersections between the horizontal and vertical strips coincide with the corresponding lamps in the eld. This grid of photosensitive strips may be formed as shown with all of the horizontal strips on one side and all of the vertical strips on the other side, or the strips may be woven in any desired manner. A woven structure would be particularly easy to 0btain if the individual strips were made of a flexible material such as cloth or of some pliable substance.

The light from the lamps in the panel |02 is directed selectively to the associated cross-points in the photo-sensitive grid by means of a lightshielding structure located between the lamp panel and the grid. 'I'his structure comprises a series of horizontal plates or shields ||2, ||3. ||4, separating the successive rows of horizontal lamps together with a series of vertical shields or plates ||5, ||6, ||8, etc., separating the successive rows of vertical lamps. These shields form cubical cells for the lamps in the panel, coniining the light for the respective lamps and causing it to shine only on the horizontal and vertical light-sensitive strips which intersect at the point opposite the associated lamp. This construction is more clearly understood from the details of Figs. 2 and 3. In Fig. 3, for example, it will be seen that the light shining from the signal lamp ||9 is conned to the cell formed by the shields ||2, H3, ||6 and and is-permitted to impinge only upon the photo-sensitive strips |05 and |08. Similarly the light shining from the lamp |20 is confined to the cellformed by shields ||3, H4, ||1 and ||8 and is permitted to'impinge only upon the photo-sensitive strips |06 and |09. Although the precise location of the horizontal and vertical strips of the grid structure with respect to the signal lamps may be adjusted as desired, the intersecting points of the strips are shown in Fig. 3 in a displaced position relative to the lamps. This will be seen by observing the location of the lamp ||9 with respect to the area of intersection formed by the associated strips |05 and |08. By displacing the intersecting area of the strips with respect to the center of the lamp it is possible to obtain a better distribution of the light upon the intersecting strips.

The one hundred .horizontal photo-sensitive strips are connected respectively to individual amplifiers 2| |22, |23, and thence through a connector, if desirable, to the registering and identifying mechanism |24. Similarly, the hundred vertical photo-sensitive strips |01, |08, |09, etc., are connected through individual ampliers |25, |26, through a connector to said registering and identifying mechanism.

Each of the individual signal lamps in the panel 02 is connectedl to the sleeve or control conductor of the subscribers line which it represents, and the current for lighting the lamp is transmitted over this control conductor as will be explained more fully hereinafter.

A description will now be given of the operation involved in the process of identifying a subscribers line. Assume for this purpose that the 'subscriber of line |00 desires to make a toll call 'for Which a ticket should be prepared to record the nature of the call andthe charge therefor.

When the subscriber initiates the call, the line finder F finds his line and extends it to the usual pulsing mechanism associated with the selector switch S. The switch S andthe switch S| respond successively to the subscribers d ial |21 to extend his line to an idle trunk |0| outgoing in the desired direction. At any suitable time during the extension of the connection of the subscribers line to the trunk |0|, an idle registering and identifying mechanism |24 is associated with the connection. The connection of the mechanism |24 with the controlling circuits |28 of the trunk 0| is eected by a-suitable connectfor printing the designation of the called subscribers line.

As soon as the mechanism |24 is ready to receive the identification of the calling line |00, it- Iestablishes connection with the identifying lamp panel |02 through suitable connectors provided for that purpose. Also a circuit is closed from the source of energy over conductor ISI, connector |29, conductor |82, thence over the sleeve conductor through the switches S-I, S and F to the sleeve conductor |00 of the subscriber's line |00. The circuit is completed from conductor |22 through a condenser |04 to the lamp |00 which is individual to the 1ine` |00 land occupies the numerical position in the .panel |02 corresponding to the number of the line. Light from the lamp shines on the photoelectric strips |00 and ||0 causing a change in the current flow in circuits and |21. These currents are amplified by the amplifiers |2| and |20 and are then delivered to the registering and identifying mechanism 24. Any suitable means may be provided in the mechanism 24 to respond to these currents and to register the designation of the line |00. Thereafter the registered infomation may be transferred to the controlling circuits |20 where it serves to operate a ticket printer to print the number of the subscribers line together with the other infomation about the call. After all the necessary operations have been performed, the identifying mechanism |24 is disconnected from the lamp panel |02 and from the controlling circuits |28.

The mechanism |24 corresponds in its purposes and operation and, if desirable, may also correspond in large measure with the structure of the register-sender and identifying mechanisms fully disclosed and described in Gooderham Patent 2,300,829 of November 3, 1942, and in the application of Gooderham, Serial No. 448,782 filed June 27, 1942. The registers on which the thousands, hundreds, tens and units digits of the calling line number are registered may be the wellknown relay registers which are so universally used in register senders of the automatic telephone art. The amplified currents flowing over the thousands and hundreds leads from the photosensltive strips |03, |04, etc., operate the corresponding thousands and hundreds relay registers in the mechanism |24; and, similarly, the currents flowing over the tens and units leads from the photo-sensitive strips |01, i00, etc., operate the tens and units relay registers in said mechanism. Reference, therefore, is made to the patent andl to the application above noted for a i'ull understanding of the manner in which the mechanism 24 is seized in response to the dialing by the calling subscriber, and connected to the ticketing trunk |0| through the connector |29y of the manner in which the .digits ofthe called line are registered in mechanism |24, of the manner in which the tone current is sent from source |20 over the sleeve of the connection to cause the identifying circuits to identify the particular line calling and to register the digits of the number of this line in the mechanism |24, and of the manner in which these identification systems operate in any other respect that may be helpful to an understanding of the application of the present invention.

What is claimed is:

l. In a telephone system, in which the lines oi' a group have designations, each of which comprises a plurality of characters, said characters varying in value from line to line, the combination of a plurality of signal lamps individual respectively to said lines. said lamps being arrayed in a neld in coordinate rows, the order of the individual lamps in said rows bearing a definite relation to the values of the designation characters of said lines, a plurality of light-sensitive strips arranged in an intersecting array and disposed in coincident relation to said ileld of lamps, means for illuminating the particular one of said lamps corresponding to any desired line of said group, the light therefrom shiningon and serving to energize the pair of light-sensitive strips having their intersection coincident to said illuminated lamp, and means responsive to the pair of energized strips for identifying the designation of said desired line.

2. In a signaling system having a group of lines provided with individual designations, each oi which has a plurality of digital characters, the combination of a plurality of signal lamps individual respectively to said lines, said lamps being arrayed in a field of coordinate horizontal and vertical rows, the order of the individual lamps in said rows bearing a definite relation to the values of the designation characters of said lines, a series of light-sensitive elements, one for each horizontal row of lamps, each of said elements arranged adjacent to the row of lamps it represents, a second series of light-sensitive elements representing respectively the vertical rows of lamps. each of the elements of said second series being arranged adjacent the lamps of the vertical row it represents, means for illuminating the particular one of said lamps corresponding to any desired line of said group, the light therefrom shining on and energizing the pair of light-sensitive elements which represent the intersecting horizontal and vertical rows containing the illuminated lamp, and means responsive to the energized light-sensitive elements for identifying the designation of said desired line.

3. In a signaling system having a group of lines provided with individual designations, each of which has a plurality of digital characters, the combination of a .plurality of signal lamps individual respectively to said lines. said lamps being arrayed in a field of coordinate horizontal and vertical rows, the order of the individual lamps in said rows bearing a deilnite relation to the values of the designation characters of said lines, a series of horizontally arranged lightsensitive strips, one for each of said horizontal rows of lamps, a second series of vertically arranged light-sensitive strips, one for each vertical row of lamps, said horizontal and vertical strips forming a grid structure disposed with the coordinate points of intersection coinciding with the signal lamps of said field, light shields interposed between the lamps of said ileld and said grid structure of light-sensitive strips for guiding the light from each lamp selectively to the corresponding pair of intersecting strips, means for lighting any lamp in said field to energize the associated .pair oi.' light-sensitive strips, and means controlled by the energized strips for identifying the designation of the corresponding line.

4. In a signaling system comprising a group of lines having individual designations, each of which comprises a plurality of digital characters, the combination of a plurality of signal lamps individual respectively to said lines, saidlamps being arranged in a field in rows, the order of the individual lamps in said rows bearing a definite relation to the values of the designation characters of said lines, a plurality oi' lightsensitive elements, one for each of said rows of lamps, each light-sensitive element comprising a mounting strip. a pair of conductors amxed t0 said strip and a light-sensitive substance covering the surface oi. said strip and said conductors, a circuit for each of said light-sensitive elements connected to the conductors thereof, means for causing the light from the lamps in each of said rows to impinge upon the associated light-sensil0 tive element to produce a change of current iiow in the associated circuit. means for illuminating connected tothe corresponding light-sensitive 

